Detachable buttress material retention systems for use with a surgical stapling device

ABSTRACT

Systems of releasably connecting staple line buttress material to the jaws of a surgical stapling instrument are provided. The systems include retainers configured to engage the buttress material and releasably retain the buttress material on the jaws of the surgical stapling instrument prior to stapling tissue. In certain embodiments, the retainers remain with the jaws of the instrument after stapling of tissue. In alternative embodiments, the retainers remain with the buttress material after being stapled to tissue.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/915,519, filed Oct. 29, 2010, which is a divisional claiming thebenefit of and priority to U.S. patent application Ser. No. 11/821,330,filed Jun. 22, 2007, now U.S. Pat. No. 7,845,533, and the disclosures ofeach of the above-identified applications are hereby incorporated byreference in their entirety.

BACKGROUND

1. Technical field

The present disclosure relates to attachment systems for staple linebuttress materials. More particularly, the present disclosure relates tosystems and methods of temporarily attaching staple line buttressmaterials to an anvil and staple containing cartridge of a surgicalstapling instrument.

2. Background Of Related Art

Surgical stapling instruments, or “stapling devices”, are employed bysurgeons to sequentially or simultaneously apply one or more rows offasteners, e.g., staples or two-part fasteners, to body tissue for thepurpose of joining segments of body tissue together. Such devicesgenerally include a pair of jaws or finger-like structures between whichthe body tissue to be joined is placed. When the stapling device isactuated, or “fired”, longitudinally moving firing bars contact stapledrive members in one of the jaws. The staple drive members push thesurgical staples through the body tissue and into an anvil in theopposite jaw which crimps the staples closed. If tissue is to be removedor separated, a knife blade can be provided in the jaws of the device tocut the tissue between the lines of staples.

When stapling relatively thin or fragile tissues, it is important toeffectively seal the staple line against air or fluid leakage.Additionally, it is often necessary to reinforce the staple line againstthe tissue to prevent tears in the tissue or pulling of the staplesthrough the tissue. One method of preventing tears or pull throughinvolves the placement of a biocompatible fabric reinforcing material,or “buttress” material, between the staple and the underlying tissue. Inthis method, a layer of buttress material is placed against the tissueand the tissue is stapled in conventional manner. In more recentmethods, the buttress material is positioned on the stapling instrumentitself prior to stapling the tissue. An exemplary example of this isdisclosed in U.S. Pat. No. 5,542,594 to McKean et al. In McKean et al.,a tube of buttress material is slipped over the jaw of the stapler. Thestapler is then actuated to staple the subject tissue and secure thebuttress material between the tissue and staple line to reinforce thetissue and staple line.

When positioning the buttress material on the jaws of the surgicalstapler, it is desirable to releasably retain the buttress materialagainst the jaws. Thus, it is desirable to provide retainers forreleasably retaining the buttress material against the jaws of thesurgical instrument.

SUMMARY

There is disclosed a surgical stapler for deploying staples in tissue,the surgical stapler has a pair of jaws for engaging tissue, including astapler cartridge and an anvil, where at least one of the jaws defines aplurality of recesses. A staple line buttress material is positioned onone of the jaws and a plurality of retainers pass through the stapleline buttress material. Each of the retainers is disposed within one ofthe recesses in the jaws so as to releasably retain the staple linebuttress material on the at least one jaw.

In one embodiment, the retainer is a staple having a backspan and a pairof legs extending from the backspan and the recesses in the at least onejaw defines a pair of holes, the legs of the staple pass through theholes such that tips of the legs are crimped over the staple linebuttress material.

In another embodiment, the legs of the staple are inserted through thestaple line buttress material such that the legs of the staple arepartially positioned within the recesses and the backspan of the staplesecures the staple line buttress material to the at least one jaw. In amore specific embodiment, the legs of the staple are crimped within therecesses.

In certain embodiments, the staple line buttress material includes aplurality of slots and the recesses are also formed as slots. Theretainers are clips passing through the slots in the staple linebuttress material and the jaw. In one embodiment, the retainer is a cliphaving an a plate and an angled lip extending from the plate, the angledlip engaging the staple line buttress material. The clip has an anglededge along one side, the angled edge being engagable with a driver ofthe surgical stapler.

In a further embodiment, the clip is an I-beam having a center portionand upper and lower beams extending from ends of the center portion. Anunderside of the upper beam engages the staple line buttress materialand ends of the lower beam frictionally engage surfaces defining therecesses.

In certain embodiments, the retainer is absorbable within the body of apatient.

There is also disclosed a method of applying staple line buttressmaterial to a surgical staple line. The method includes providing asurgical stapler having a pair of jaws including a staple containingcartridge and an anvil, the surgical stapler having a buttress materialreleasably disposed on at least one of the jaws and a plurality ofretainers passing through the staple line buttress material and intorecesses formed in the at least one jaw.

In the disclosed method the surgical stapler is actuated to drivestaples contained in the staple containing cartridge through thebuttress material and tissue captured between the jaws and into theanvil so as to staple the buttress material to the tissue. In oneembodiment of the method, the retainers are retained within the at leastone jaw after the buttress material has been stapled to the tissue. Inan alternative embodiment of the disclosed method, the retainers areretained on the buttress material after the buttress material has beenstapled to the tissue.

In one embodiment of the disclosed method the retainers are reversestaples frictionally retained within the recesses while in analternative embodiment of the disclosed method the retainers are clipspassing through the buttress material. A surface of the clips engage thebuttress material.

DESCRIPTION OF THE DRAWINGS

Various embodiments of the presently disclosed systems for attachingstaple line buttress materials to a surgical stapling instrument aredisclosed herein with reference to the drawings, wherein:

FIG. 1 is a perspective view of a surgical stapling instrumentincorporating embodiments of retention systems for attachment of stapleline buttress materials to an anvil and a staple cartridge:

FIG. 2 is an enlarged perspective view of the distal end of the surgicalstapling instrument of FIG. 1;

FIG. 3 is a perspective view, with parts separated, of one embodiment ofan anvil and buttress material retention system;

FIG. 4 is a perspective view, partially shown in section, taken alongline 4-4 of FIG. 2;

FIG. 5 is a side view, partially shown in section, taken along line 5-5of FIG. 3 illustrating initial assembly of an anvil buttress retentionsystem;

FIG. 6 is a side view, partially shown in section, illustrating thepartial crimping of a retaining clip of the anvil buttress retentionsystem;

FIG. 7 is a perspective view, with parts separated, of one embodiment ofa staple cartridge and buttress material retention system;

FIG. 8 is a perspective view of a staple cartridge assembly illustratingthe partially assembled staple cartridge buttress retention system;

FIG. 9 is a side view, partially shown in section, taken along line 9-9of FIG. 8;

FIG. 10 is a side view, partially shown in section, similar to FIG. 9,illustrating crimping of a reverse staple of the staple cartridgebuttress retention system;

FIG. 11 is a perspective view of the distal end of the surgical staplinginstrument of FIG. 1 positioned about a tissue section;

FIG. 12 is a cross-sectional view of the tissue section positionedbetween the anvil assembly and the cartridge assembly of the surgicalstapling instrument of FIG. 1;

FIG. 13 is a cross-sectional view, similar to FIG. 12, during initialactuation of the surgical stapling instrument of FIG. 1;

FIG. 14 is a cross-sectional view, similar to FIG. 13, during actuationof the surgical stapling instrument to staple the tissue section;

FIG. 15 is a cross-sectional view, similar to FIG. 14, after actuationillustrating release of the stapled tissue section;

FIG. 16 is a perspective view of the stapled tissue section withbuttress materials attached;

FIG. 17 is a cross-sectional view taken along line 17-17 of FIG. 16;

FIG. 18 is an enlarged perspective view of the distal end of thesurgical stapling instrument of FIG. 1 incorporating alternativeembodiments of retention systems for attachment of staple line buttressmaterials to an anvil and staple cartridge;

FIG. 19 is a perspective view, with parts separated, of anotherembodiment of an anvil and buttress material retention system inaccordance with FIG. 18;

FIG. 20 is a perspective view of a retention clip of the anvil buttressretention system of FIG. 19;

FIG. 21 is a perspective view, partially shown in section, taken alongline 21-21 of FIG. 18;

FIG. 22 is a perspective view of an alternative retention clip for usein the anvil buttress retention system of FIG. 18;

FIG. 23 is a perspective view of a further alternative retention clipfor use in the anvil buttress retention system of FIG. 18;

FIG. 24 is a perspective view, with parts separated, of anotherembodiment of a staple cartridge and buttress material retention systemin accordance with FIG. 18;

FIG. 25 is a perspective view of a staple illustrating the partiallyassembled staple cartridge buttress retention system of FIG. 24;

FIG. 26 is a side view, partially shown in section, illustrating theinsertion of a reverse staple being inserted into a staple pocket;

FIG. 27 is a side view, partially shown in section, illustrating thereverse staple frictionally retained in the staple pocket;

FIG. 28 is a perspective view of the distal end of the surgical staplinginstrument illustrated in FIG. 18 positioned about a tissue section;

FIG. 29 is a cross-sectional view taken along the line 29-29 of FIG. 28;

FIG. 30 is a cross-sectional view, similar to FIG. 29, during initialactuation;

FIG. 31 is a cross-sectional view, similar to FIG. 30, during actuationto staple the tissue section;

FIG. 32 is a cross-sectional view, similar to FIG. 31, after actuationillustration release of the stapled tissue section;

FIG. 33 is a perspective view of the stapled tissue section withbuttress material attached;

FIG. 34 is side view, partially shown in section, taken along line 34-34of FIG. 33;

FIG. 35 is an enlarged perspective view of the distal end of thesurgical stapling instrument of FIG. 1 incorporating further alternativeembodiments of retention systems for attachment of staple line buttressmaterials to an anvil and staple cartridge;

FIG. 36 is a perspective view, with parts separated, of a staplecartridge buttress retention system in accordance with FIG. 35;

FIG. 37 is a perspective view of an I-beam retention clip of the staplecartridge buttress retention system of FIG. 36;

FIG. 38 is a side view, partially shown in section, of the I-beamretention clip frictionally retained within the staple cartridge;

FIG. 39 is a cross-sectional view of a tissue section positioned betweenthe anvil and cartridge assemblies of FIG. 35;

FIG. 40 is a cross-sectional view, similar to FIG. 39, during initialactuation;

FIG. 41 is a cross-sectional view, similar to FIG. 40, during actuationto staple the tissue section;

FIG. 42 is a cross-sectional view, similar to FIG. 41, after actuationillustrating release of the stapled tissue section;

FIG. 43 is a perspective view of the stapled tissue section; and

FIG. 44 is a cross-sectional view of the stapled tissue section takenalong line 44-44 of FIG. 43.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed detachable buttress materialretention systems for use with surgical stapling instruments will now bedescribed in detail with reference to the drawings wherein like numeralsdesignate identical or corresponding elements in each of the severalviews. As is common in the art, the term ‘proximal” refers to that partor component closer to the user or operator, i.e. surgeon or physician,while the term “distal” refers to that part or component further awayfrom the user.

Referring now to FIG. 1, there is disclosed a linear surgical staplinginstrument or surgical stapler 10 for use in stapling tissue andapplying layers of buttress material between the staples and underlyingtissue. An exemplary example of this type of surgical staplinginstrument is disclosed in U.S. Pat. No. 7,128,253, the entiredisclosure of which is incorporated by reference herein. Surgicalstapler 10 generally includes a handle 12 having an elongate tubularmember 14 extending distally from handle 12. A jaw assembly 16 ismounted on a distal end 18 of elongate tubular member 14. Jaw assembly16 includes a staple clinching anvil 20 and a staple containingcartridge or staple cartridge 22. Staple cartridge 22 may be permanentlyaffixed to elongate tubular member 14 or may be detachable and thusreplaceable with a new staple cartridge 22. Staple clinching anvil 20 ismovably mounted on distal end 18 of elongate tubular member 14 and ismovable between an open position spaced apart from staple cartridge 22to a closed position substantially adjacent staple cartridge 22.

Staple clinching anvil 20 is provided with a layer of anvil buttressmaterial 24 and staple cartridge 22 is provided with a layer ofcartridge buttress material 26 in the manners described in more detailhereinbelow. A plurality of anvil buttress retainers in the form ofclips or reverse staples 28 are provide to releasably secure anvilbuttress material to staple clinching anvil 20. Likewise, a plurality ofcartridge buttress retainers in the form of detachable clips or reversestaples 30 are provided to releasable secure cartridge buttress material26 to staple cartridge 22. Anvil buttress material 24 and cartridgebuttress material 26 are provided to reinforce and seal staple linesapplied to tissue by surgical stapler 10.

Surgical stapler 10 includes a trigger 32 movably mounted on handle 12.Actuation of trigger 32 initially operates to move anvil 20 from theopen to the closed position relative to staple cartridge 22 andsubsequently actuate surgical stapler 10 to apply lines of staples totissue. In order to properly orient jaw assembly 16 relative to thetissue to be stapled, surgical stapler 10 is additionally provided witha rotation knob 34 mounted on handle 12. Rotation of rotation knob 34relative to handle 12 rotates elongate tubular member 14 and jawassembly 16 relative to handle 12 so as to properly orient jaw assembly16 relative to the tissue to be stapled.

Referring to FIG. 2, a driver 36 is provided to move anvil 20 betweenthe open and closed positions relative to staple cartridge 22. Driver 36moves between a longitudinal slot 38 formed in anvil 20. A knife blade(not shown) is associated with driver 32 to cut tissue captured betweenanvil 20 and staple cartridge 22 as driver 36 passes through slot 38.

Anvil 20, anvil buttress material 24 and anvil buttress retainers orreverse staples 28 combine to form an anvil buttress attachment system40 allowing anvil buttress material 24 to be supported on and releasablyaffixed to anvil 20. Similarly, staple cartridge 22, cartridge buttressmaterial 26 and cartridge buttress retainers or reverse staples 30combine to form a cartridge buttress attachment system 42 allowingcartridge buttress material 26 to be supported on and releasably affixedto staple cartridge 22. Anvil buttress attachment system 40 andcartridge buttress attachment system 42 are particularly configured toallow the respective buttress materials to be localized on inwardlyfacing surfaces of anvil 20 and staple cartridge 22 in order tofacilitate passage of surgical stapler 10 into the body of a patientwithout risk of tearing or wrinkling of the respective buttressmaterials as surgical stapler 10 is inserted into and manipulated withinthe body of a patient.

Referring to FIG. 3, in order to move anvil 20 between the open andclosed positions, anvil 20 includes a proximal, angled or sloped edge 44configured to be engaged by driver 36 in order to cam anvil 20 to theclosed position. Slot 38 extends distally from sloped edge 44 andterminates in a transverse slot 46 which is configured to capture driver36 upon complete actuation of surgical stapler 10 to prevent any furtheractuation of surgical stapler 10. In order to secure staples provided bystaple cartridge 22 about the tissues and buttress materials, anvil 20is provided with longitudinally extending rows of staple clinchingpockets 48 located on either side of longitudinal slot 38. While only asingle row of staple clinching pockets 48 is illustrated on either sideof slot 38, it is contemplated that multiple and/or staggered rows ofstaple clinching pockets 48 may be provided on anvil 20.

Referring still to FIG. 3, anvil buttress attachment system 40,including anvil 20, anvil buttress material 24 and anvil buttressretainers or reverse staples 28 will now be described. Anvil buttressmaterial 24, as well as cartridge buttress material 26. The buttressmaterial for the staple cartridge 22 and/or anvil 20 may be made fromany biocompatible natural or synthetic material. The material from whichthe buttress material is formed may be bioabsorbable ornon-bioabsorbable. It should of course be understood that anycombination of natural, synthetic, bioabsorbable and non-bioabsorbablematerials may be used to form the buttress material.

Some non-limiting examples of materials from which the buttress materialmay be made include but are not limited to polylactic acid),poly(glycolic acid), poly(hydroxybutyrate), poly(phosphazine),polyesters, polyethylene glycols, polyethylene oxides, polyacrylamides,polyhydroxyethylmethylacrylate, polyvinylpyrrolidone, polyvinylalcohols, polyacrylic acid, polyacetate, polycaprolactone,polypropylene, aliphatic polyesters, glycerols, poly(amino acids),copoly(ether-esters), polyalkylene oxalates, polyamides,poly(iminocarbonates), polyalkylene oxalates, polyoxaesters,polyorthoesters, polyphosphazenes and copolymers, block copolymers,homopolymers, blends and combinations thereof.

In embodiments, natural biological polymers are used in forming thebuttress material. Suitable natural biological polymers include, but arenot limited to, collagen, gelatin, fibrin, fibrinogen, elastin, keratin,albumin, hydroxyethyl cellulose, cellulose, hydroxypropyl cellulose,carboxyethyl cellulose, chitan, chitosan, and combinations thereof. Inaddition, the natural biological polymers may be combined with any ofthe other polymeric materials described herein to produce the buttressmaterial.

The buttress material may be porous or non-porous, or combinations ofporous and non-porous layers. Where the buttress material is non-porous,buttress material may retard or prevent tissue ingrowth from surroundingtissues thereby acting as an adhesion barrier and preventing theformation of unwanted scar tissue. Thus, in embodiments, the buttressmaterial possesses anti-adhesion properties. Techniques for formingnon-porous layers from such materials are within the purview of thoseskilled in the art and include, for example, casting, molding and thelike.

In embodiments, the buttress material is porous and possesses hemostaticproperties. Where the buttress material is porous, it has openings orpores over at least a portion of a surface thereof. Suitable materialsfor forming the porous layer include, but are not limited to foams(e.g., open or closed cell foams). In embodiments, the pores may be insufficient number and size so as to interconnect across the entirethickness of the porous layer. In other embodiments, the pores do notinterconnect across the entire thickness of the porous layer. In yetother embodiments, the pores do not extend across the entire thicknessof the porous layer, but rather are present at a portion of the surfacethereof. In embodiments, the openings or pores are located on a portionof the surface of the porous layer, with other portions of the porouslayer having a non-porous texture. Those skilled in the art reading thepresent disclosure will envision other pore distribution patterns andconfigurations for the porous layer.

Where the buttress material is porous, the pores may be formed using anymethod suitable to forming a foam or sponge including, but not limitedto the lyophilization or freeze-drying of a composition. Suitabletechniques for making foams are within the purview of those skilled inthe art. Porous buttress materials can be at least 0.2 cm thick, inembodiments from about 0.3 to about 1.5 cm thick. Porous buttressmaterials can have a density of not more than about 75 mg/cm² and, inembodiments below about 20 mg/cm². The size of the pores in the porousbuttress materials can be from about 20 μm to about 300 μm, inembodiments from about 100 μm to about 200 μm.

The buttress material may also include a reinforcement member. Thereinforcement member may be associated with a porous or non-porous layeror may be positioned between a non-porous layer and a porous layer ofthe buttress material. Alternatively, the reinforcement member may bepositioned entirely within one or more of the individual layers (i.e.,embedded within the porous layer, the non-porous layer, or both) of thebuttress material. It is also envisioned that the reinforcement membermay be positioned at the surface of one of the layers making up thebuttress material and, in embodiments, may be positioned at an exteriorsurface of the buttress material.

Some suitable non-limiting examples of reinforcement members includefabrics, meshes, monofilaments, multifilament braids, chopped fibers(sometimes referred to in the art as staple fibers) and combinationsthereof. Where the reinforcement member is a mesh, it may be preparedusing any technique known to those skilled in the art, such as knitting,weaving, tatting, knipling or the like. Where monofilaments ormultifilament braids are used as the reinforcement member, themonofilaments or multifilament braids may be oriented in any desiredmanner. For example, the monofilaments or multifilament braids may berandomly positioned with respect to each other within the buttressmaterial. As another example, the monofilaments or multifilament braidsmay be oriented in a common direction within the buttress material.Where chopped fibers are used as the reinforcement member, the choppedfibers may be oriented in any desired manner. For example, the choppedfibers may be randomly oriented or may be oriented in a commondirection. The chopped fibers can thus form a non-woven material, suchas a mat or a felt. The chopped fibers may be joined together (e.g., byheat fusing) or they may be unattached to each other. The chopped fibersmay be of any suitable length. For example, the chopped may be from 0.1mm to 100 mm in length, in embodiments, 0.4 mm to 50 mm in length. In anillustrative embodiment, the buttress material has randomly orientedchopped fibers that have not been previously fused together embeddedwithin in the buttress material.

It is envisioned that the reinforcement member may be formed from anybioabsorbable, non-bioabsorbable, natural, or synthetic materialpreviously described herein and combinations thereof. Wheremonofilaments or multifilament braids are used as the reinforcementmember, any commercially available suture material may advantageously beemployed as the reinforcement member.

In embodiments, at least one bioactive agent may be combined with thebuttress material and/or any of the individual components (the porouslayer, the non-porous layer and/or the reinforcement member) used toconstruct the buttress material. In these embodiments, the buttressmaterial can also serve as a vehicle for delivery of the bioactiveagent. The term “bioactive agent”, as used herein, is used in itsbroadest sense and includes any substance or mixture of substances thathave clinical use. Consequently, bioactive agents may or may not havepharmacological activity per se, e.g., a dye, or fragrance.Alternatively a bioactive agent could be any agent which provides atherapeutic or prophylactic effect, a compound that affects orparticipates in tissue growth, cell growth, cell differentiation, ananti-adhesive compound, a compound that may be able to invoke abiological action such as an immune response, or could play any otherrole in one or more biological processes.

Examples of classes of bioactive agents which may be utilized inaccordance with the present disclosure include anti-adhesives,antimicrobials, analgesics, antipyretics, anesthetics, antiepileptics,antihistamines, anti-inflammatories, cardiovascular drugs, diagnosticagents, sympathomimetics, cholinomimetics, antimuscarinics,antispasmodics, hormones, growth factors, muscle relaxants, adrenergicneuron blockers, antineoplastics, immunogenic agents,immunosuppressants, gastrointestinal drugs, diuretics, steroids, lipids,lipopolysaccharides, polysaccharides, and enzymes. It is also intendedthat combinations of bioactive agents may be used.

Anti-adhesive or anti-adhesion agents can be used to prevent adhesionsfrom forming between the buttress material and the surrounding tissuesopposite the target tissue. Some examples of these agents include, butare not limited to poly(vinyl pyrrolidone), carboxymethyl cellulose,hyaluronic acid, polyethylene oxide, poly vinyl alcohols andcombinations thereof.

Suitable antimicrobial agents which may be included as a bioactive agentin the buttress material of the present disclosure include triclosan,also known as 2,4,4′-trichloro-2′-hydroxydiphenyl ether, chlorhexidineand its salts, including chlorhexidine acetate, chlorhexidine gluconate,chlorhexidine hydrochloride, and chlorhexidine sulfate, silver and itssalts, including silver acetate, silver benzoate, silver carbonate,silver citrate, silver iodate, silver iodide, silver lactate, silverlaurate, silver nitrate, silver oxide, silver palmitate, silver protein,and silver sulfadiazine, polymyxin, tetracycline, aminoglycosides, suchas tobramycin and gentamicin, rifampicin, bacitracin, neomycin,chloramphenicol, miconazole, quinolones such as oxolinic acid,norfloxacin, nalidixic acid, pefloxacin, enoxacin and ciprofloxacin,penicillins such as oxacillin and pipracil, nonoxynol 9, fusidic acid,cephalosporins, and combinations thereof. In addition, antimicrobialproteins and peptides such as bovine lactoferrin and lactoferricin B maybe included as a bioactive agent in the bioactive coating of the presentdisclosure.

Other bioactive agents which may be included as a bioactive agent in thebuttress material in accordance with the present disclosure include:local anesthetics; non-steroidal antifertility agents;parasympathomimetic agents; psychotherapeutic agents; tranquilizers;decongestants; sedative hypnotics; steroids; sulfonamides;sympathomimetic agents; vaccines; vitamins; antimalarials; anti-migraineagents; anti-parkinson agents such as L-dopa; anti-spasmodics;anticholinergic agents (e.g. oxybutynin); antitussives; bronchodilators;cardiovascular agents such as coronary vasodilators and nitroglycerin;alkaloids; analgesics; narcotics such as codeine, dihydrocodeinone,meperidine, morphine and the like; non-narcotics such as salicylates,aspirin, acetaminophen, d-propoxyphene and the like; opioid receptorantagonists, such as naltrexone and naloxone; anti-cancer agents;anti-convulsants; anti-emetics; antihistamines; anti-inflammatory agentssuch as hormonal agents, hydrocortisone, prednisolone, prednisone,non-hormonal agents, allopurinol, indomethacin, phenylbutazone and thelike; prostaglandins and cytotoxic drugs; estrogens; antibacterials;antibiotics; anti-fungals; anti-virals; anticoagulants; anticonvulsants;antidepressants; antihistamines; and immunological agents.

Other examples of suitable bioactive agents which may be included in thecoating composition include viruses and cells, peptides, polypeptidesand proteins, analogs, muteins, and active fragments thereof, such asimmunoglobulins, antibodies, cytokines (e.g. lymphokines, monokines,chemokines), blood clotting factors, hemopoietic factors, interleukins(IL-2, IL-3, IL-4, IL-6), interferons (β-IFN, (α-IFN and γ-IFN),erythropoietin, nucleases, tumor necrosis factor, colony stimulatingfactors (e.g., GCSF, GM-CSF, MCSF), insulin, anti-tumor agents and tumorsuppressors, blood proteins, gonadotropins (e.g., FSH, LH, CG, etc.),hormones and hormone analogs (e.g., growth hormone), vaccines (e.g.,tumoral, bacterial and viral antigens); somatostatin; antigens; bloodcoagulation factors; growth factors (e.g., nerve growth factor,insulin-like growth factor); protein inhibitors, protein antagonists,and protein agonists; nucleic acids, such as antisense molecules, DNAand RNA; oligonucleotides; polynucleotides; and ribozymes.

Referring now to FIGS. 3-6, and initially with regard to FIGS. 3 and 5,the details of anvil buttress retention system 40 will now be described.As noted above, anvil buttress retention system 40 includes clip orreverse staple 28 to secure anvil buttress material 24 to anvil 20.Reverse staple 28 has a span or back span 50 having a pair of legs 52and 54 extending from backspan 50. Legs 52 and 54 terminate in sharptips 56 and 58, respectively, which are provided to penetrate anvilbuttress material 24 as anvil retention system 40 is assembled.

As noted above, anvil 20 is provided with rows of staple clinchingpockets 48. In this embodiment, pairs of holes 60 are drilled in anvil20 to allow legs 52 and 54 of reverse staples 28 to pass therethrough.Pairs of holes 60 are positioned in line with rows of staple clinchingpockets 48 and take the place of one or more sets of staple clinchingpockets 48 within the rows as shown. In a specific embodiment, pairs ofholes 60 are located in the outer most rows of staple clinching pockets48 to secure anvil buttress material 24 along its outer edges.

Referring now to FIGS. 3-6, in order to assemble anvil buttressretention system 40, legs 52 and 54 of reverse staples 28 are insertedthrough pairs of holes 60 in anvil 20 such tips 56 and 58 penetrateanvil buttress material 24 (FIG. 5). Alternatively, anvil buttressmaterial 24 may be provided with preformed holes to accommodate legs 52and 54. Once legs 52 and 54 have been positioned through anvil 20 andanvil buttress material 24, legs 52 and 54 are bent or crimped to forminwardly bent legs 62 and 64 (see FIG. 6) which secure anvil buttressmaterial 24 against anvil 20. As shown, backspan 50 of reverse staple 28is adjacent a top side 66 of anvil 20 while anvil buttress material 24is secured against an underside 68 of anvil 20 by inwardly bent legs 62and 64 (FIGS. 4 and 6). The length of inwardly bent legs 62 and 64 issufficiently short such that anvil buttress material 24 can pull awayfrom anvil 20 once anvil buttress material 24 has been stapled totissue.

Referring now to FIGS. 7-10, the details and assembly of cartridgebuttress retention system 42 will now be described. Referring initiallyto FIG. 7, and as noted above, cartridge buttress retention system 42generally includes staple cartridge 22, cartridge buttress material 26and detachable clips or reverse staples 30 releasably securing cartridgebuttress material 26 to staple cartridge 22. Reverse staples 30 aresimilar to the staples, described below, used to staple tissue. Incontrast to reverse staples 28 associated with anvil buttress retentionsystem 40 described above, reverse staples 30 are intended to detachfrom staple cartridge 22 and travel with cartridge buttress material 26as cartridge buttress material 26 is stapled to a body. Reverse staples30 are formed of a biocompatible material and may be formed from anabsorbable or resorbable material so as to deteriorate within the bodyover time. In contrast to reverse staples 28 associated with anvilbuttress retention system 40 described above, reverse staples 30 areintended to detach from staple cartridge 22 and travel with cartridgebuttress material 26 as cartridge buttress material 26 is stapled to abody.

Staple cartridge 22 generally includes a plastic body portion 70 and anouter channel 72. Staple cartridge 22 is supported on elongate tubularmember 14 by outer channel 72. Body portion 70 includes a plurality ofrows of staple containing pockets 74 provided to contain staples used tostaple tissue as described below. A knife channel 78 is positionedbetween rows of staple containing pockets 74 for passage of a knife usedto cut the stapled tissue along with cartridge buttress material 26.

Rows of staple containing pockets 74 include longitudinally spaced,empty or dummy pockets 78 for receipt of reverse staples 30 in order tosecure cartridge buttress material 26 to staple cartridge 22.

As shown in FIG. 8, in order to assemble cartridge buttress retentionsystem 42, cartridge buttress material 26 is positioned over bodyportion 70 of staple cartridge 22 and reverse staples 30 are insertedthrough cartridge buttress material 26 and into dummy pockets 78 (FIG.9). With reference to FIGS. 9 and 10, a crimping die 80 is provided tofrictionally secure reverse staple 30 within dummy pocket 78.Specifically, reverse staple 30 includes a back span 82 and a pair oflegs 84 and 86 projecting from back span 82. Legs 84 and 86 terminate inpoints or tips 88 and 90, respectively.

Referring to FIGS. 9 and 10, once legs 84 and 86 have been insertedthrough cartridge buttress material 26 and into dummy pocket 78,crimping die 80 is urged upwardly within dummy pocket 78 such thatcrimping pockets 92 and 94 on crimping die 80 engage tips 88 and 90 andbend or crimp them to form crimped ends 96 and 98 (FIG. 10). Whenreverse staple 30 has been crimped within dummy pocket 78, legs 84 and86 are forced or splayed outwardly so as to frictionally engage walls100 of dummy pocket 78 thereby frictionally retaining reverse staple 30within dummy pocket 78.

Referring now to FIGS. 11 through 17, and initially with respect toFIGS. 11 and 12, the use of surgical stapler 10 to staple and divide atubular tissue section T will now be described. Initially, jaw assembly16, including anvil 20 and staple containing cartridge 22 are positionedaround the tissue T to be stapled. Driver 36 is in a proximal positionrelative to anvil slot 38. As best shown in FIG. 11, the staplecontaining insert or plastic body portion 70 includes staples 102positioned within individual staple pockets 104 of row of staple pockets74. Staples 102 are of a conventional type and include a backspan 106having a pair of legs 108 and 110 extending from backspan 106. Legs 108and 110 terminate in tissue penetrating tips 112 and 114. Pushers 116are located within staple pockets 104 and arc positioned between staples102 and the path of a drive bar 118.

Referring now to FIG. 13, surgical stapler 10 is initially actuated bymovement of trigger 32 relative to handle 12 (FIG. 1) causing driver 36to move in the direction of arrow B and against sloped edge 44 of anvil20 thereby causing anvil 20 to be moved to the closed position relativeto staple cartridge 22. As best shown in FIG. 14, as drive bar 118advances distally within plastic body portion 74, drive bar 118 urgespushers 116 upwardly against backspans 106 of staples 102 drivingstaples 102 through cartridge buttress material 26, tissue T, anvilbuttress material 24 and towards staple clinching pockets 48 in anvil20. Tissue penetrating tips 112 and 114 are bent within staple clinchingpockets 48 in anvil 20 to thereby secure anvil buttress material 24against tissue T while backspan 106 secures cartridge buttress material26 against tissue T.

While not specifically shown, upon full actuation of surgical stapler10, a knife blade associated with surgical stapler 10 and carried bydriver 36 cuts tissue T, as well as anvil buttress material 24 andcartridge buttress material 26 between the rows of now clinched staples102.

As shown in FIG. 15, in one embodiment, upon movement of anvil 20 to theopen position spaced apart from staple cartridge 22, anvil buttressmaterial 24 pulls away from anvil 20 and anvil buttress retainers 28.Specifically, anvil buttress material 24 pulls free from inwardly bentlegs 62 and 64 of anvil buttress retainers 28 leaving anvil buttressretainers 28 attached to anvil 20. In addition, as anvil 20 is moved tothe open position, cartridge buttress material 26 separates from staplecontaining cartridge 22. As noted above, cartridge buttress retainers 30are frictionally retained within dummy pockets 78. As cartridge buttressmaterial 26 pulls away from staple containing cartridge 22, cartridgebuttress retainers 30 pull free from dummy pockets 78 and remain withthe stapled tissue T and cartridge buttress material 26. As noted above,cartridge buttress retainers 30 may be formed of absorbable orresorbable materials which will degrade in the body over time.

The resulting tissue T, divided and stapled closed with staples 102, isbest illustrated in FIGS. 16 and 17. Specifically, cartridge buttressmaterial 26 is secured against tissue T by backspans 106 of staples 102and anvil buttress material 24 is secured against tissue T by the nowclinched tissue penetrating tips 112 and 114 of staples 102. In thismanner, anvil buttress material 24 and cartridge buttress material 26are stapled to tissue T thereby sealing and reinforcing these staplelines created by staples 102.

Referring now to FIGS. 18-34, there are disclosed alternativeembodiments of an anvil buttress retention system 120 and a cartridgebuttress retention system 122 for use in surgical stapling instrument10. Referring initially to FIGS.18 and 19, anvil buttress retentionsystem 120 is provided to retain anvil buttress material 24 against ananvil 124 prior to stapling to tissue. Anvil 124 is similar to anvil 20described hereinabove and includes a sloped proximal edge 136 forengagement with driver 36 in order to move anvil 124 between open andclosed positions relative to staple containing cartridge 22. Anvil 124additionally includes a slot 128 for passage of a knife associated withsurgical stapling instrument 10. Anvil buttress retention system 120includes a plurality of novel retainers or clips 130 to assist inretaining anvil buttress material 24 on anvil 124. Anvil 124 is providedwith a series of clip slots 132, for receipt of clips 130, which arespaced along staple clinching pockets 134 formed in anvil 124. Anvilbuttress material 24 also contains buttress material slots 136 forpassage of clips 130 therethrough.

Referring for the moment to FIG. 20, clip 130 is generally formed as aplate 138 having a sloped edge 140 along a first end 142 of plate 138and a flange or lip 144 projecting at approximately a right angle from asecond end 146 of plate 138. Sloped edge 140 is configured to be engagedby driver 36 to force clip 130 out of anvil 124 while lip 144 isprovided to retain anvil buttress material 24 against anvil 124 prior tostapling. As best shown in FIGS. 20 and 21, clip 130 is frictionallyretained within clip slot 132 of anvil 124 and an undersurface 148 oflip 144 retains anvil buttress material 24 against anvil 124.

In an alternative embodiment shown in FIG. 22, an alternative clip 150may be provided having a pair of spaced apart lips 152 and 154projecting at a generally right angle from a plate 156 of clip 150. Lips152 and 154 are configured to retain anvil buttress material 24 againstanvil 124 in a manner similar to that of clip 130. Clip 150 alsoincludes an angled edge 158 for engagement by driver 36 of surgicalstapling instrument 10 to separate clip 150 and anvil buttress material24 from anvil 124.

A still further embodiment of a retention clip 160 is illustrated inFIG. 23. Clip 160 is also formed as a plate 162 having an angled edge164 for engagement with driver 30 of surgical stapling instrument 10.Clip 160 is provided with a pair of opposite facing lips 166 and 168which extend generally at right angles from plate 162 to increase theamount of surface provided to secure anvil buttress material 24 to anvil124.

Referring now to FIGS. 22-27, and initially with regard to FIG. 24,cartridge buttress retention system 122 is similar to cartridge buttressretention system 42 described hereinabove, including staple containingcartridge 22 having plastic body portion 70 and outer channel 72 andcartridge buttress material 26. As described hereinabove, plastic bodyportion includes rows of staple pockets 74 separated by knife channel76. However, in place of reverse staples 30, cartridge buttressretention system 122 utilizes clips or reverse staples 182 which are notintended to be crimped within dummy pockets 78 in plastic body portion70. Rather, as best shown in FIGS. 26 and 27, legs 184 and 186 ofreverse staple 182 frictionally engage inner surfaces 100 of dummypockets 78 while a back span 188 of reverse staple 182 holds cartridgebuttress material 26 against staple containing cartridge 22.

With reference to FIGS. 28 and 29, in use, jaw assembly 16 is initiallypositioned about a tissue section T with anvil 124 in the open positionspace apart from staple containing cartridge 22. Driver 36 is in aproximal position relative to sloped proximal edge 126 of anvil 24.Clips 130 are positioned through slots 136 in anvil 124 retaining anvilbuttress material 24 against anvil 124. As discussed hereinabove,plastic body portion 70 contains staples 102 positioned within staplepockets 104. Reverse staples 182 are positioned within dummy pockets 78retaining staple buttress material 26 against staple containingcartridge 22.

Referring now to FIG. 30, upon actuation of surgical stapler 10, driver36 moves distally in the direction of arrow B and against sloped edge126 of anvil 124 causing anvil 124 to move to the closed positionrelative to staple containing cartridge 22 compressing tissue Ttherebetween.

As best shown in FIG. 31, as driver 36 continues to move distally alonganvil 124, driver 36 engages sloped edge 140 of clips 130 forcing clips130 downwardly within slots 132 in anvil 124. This initiates release ofanvil buttress material 24 from anvil 124. Identical to that describedhereinabove, as drive bar 118 advances distally in response to actuationof surgical stapler 10, drive bar 118 urges pushers 116 upwardly withinstaple pockets 104 driving tissue penetrating tips 112 and 114 of staple102 through cartridge buttress material 26, tissue T, anvil buttressmaterial 24 and into staple clinching pockets 134 in anvil 124. Tips 112and 114 are crimped within staple clinching pockets 124 thereby securinganvil buttress material 24 to tissue T. Backspans 106 of staples 102secure cartridge buttress material 26 to tissue T. As discussed above, aknife associated with surgical stapler 10 divides tissue T, as well asanvil buttress material 24 and cartridge buttress material 26, betweennow clinched rows of staples 102.

Referring for the moment to FIG. 32, upon movement of anvil 124 to theopen position, anvil buttress material pulls clips 130 out of clip slots132 in anvil 124 such that anvil buttress material 24 separates fromanvil 124. Reverse staples 182 pull free from dummy pockets 78 (FIG. 31)freeing cartridge buttress material 26 from staple cartridge 22. Thus,both reverse staples 182 and clips 130 remain with stapled tissue T and,as noted above, are formed of a degradable material which will dissolvewithin the body over time.

The resultant stapled tissue sections T are best illustrated in FIGS. 33and 34. Cartridge buttress material 26 and anvil buttress material 24are stapled to tissue T by staples 102 thereby reinforcing the stapleline formed by staples 102 and sealing the stapled and severed ends oftissue T.

Referring now to FIGS. 35-44, there is disclosed a further alternativeembodiment of a cartridge buttress retention system 190 for use withsurgical stapler 10 and anvil buttress retention system 40 describedhereinabove. Cartridge buttress retention system 190 generally includesstaple containing cartridge 22 and cartridge buttress material 26. Aplurality of cartridge buttress retainers or I-beam retainers 192 areprovided to frictionally engage staple containing cartridge 22 andtemporarily secure cartridge buttress material 26 to staple containingcartridge 22.

Referring for the moment to FIG. 37, I-beam retainer 192 generallyincludes a rectangular central portion 194 having rectangular upper beam196 and lower beam 198 attached thereto. As with the retention devicesdescribed hereinabove, retainer 192 may be formed of a material thatdegrades within the body over time. Cartridge buttress material 26includes a plurality of slots 200 which are aligned with dummy pockets78 in staple containing cartridge 22 and allow for partial passage ofI-beam retainer 192 therethrough (FIG. 36).

With continued reference to FIG. 37 and also FIG. 38, an under surface102 of upper beam 196 of I-beam retainer 192 secures cartridge buttressmaterial 26 against staple containing cartridge 22. Opposed ends 204 and206 of lower beam 198 of I-beam retainer 192 frictionally engage innersurfaces 100 of dummy pockets 78 to frictionally retain 1-beam retainer192 partially within staple containing cartridge 22.

With reference to FIGS.39-42, operation of cartridge buttress retentionsystem 190 functions similar to that of cartridge buttress retentionsystems 42 and 122 described hereinabove. Initially, jaw assembly 16 ispositioned about tissue T with anvil 20 is in the open position spacedapart from staple containing cartridge 22. Upon actuation of surgicalstapler 10, driver 36 advances distally moving anvil 20 to the closedposition (FIG.40). Drive bar 118 advance distally engaging pushers 116and driving staples 102 through cartridge buttress material 26, tissueT, anvil buttress material 24 and into staple clinching pockets 48 toclinch tips 112 and 114 of staples 102 over anvil buttress material 24(FIG. 41). Upon movement of anvil 20 to the open position, anvilbuttress material 24 pulls free from reverse staples 28. Lower beam 198is sufficiently flexible to allow I-beam retainer 192 to pull free fromdummy pocket 78 and remain affixed to cartridge buttress material 26(FIG. 42).

The resultant tissue T, divided and stapled closed with staples 102 isshown in FIGS. 43 and 44. As shown, anvil buttress material 24 andcartridge buttress material 26 are stapled to tissue T therebyreinforcing the staple lines formed by staples 102 and sealing thetissues section T. In this manner, cartridge buttress retention system190 allows cartridge buttress material 26 to be detachably retained onstaple containing cartridge 22 and released upon stapling to tissue.

It will be understood that various modifications may be made to theembodiments disclosed herein. For example, the disclosed retainers andmethods are interchangeable for use in either the staple containingcartridge or anvil. Further, the disclosed methods and retention systemsare not limited to stapling apparatus but may find application in otherinstruments and situations requiring material to be reseably retained onthe surface of a surgical instrument. Additionally, the disclosedretainers can function as both buttress material retention devices andtissue connecting devices, i.e., “tissue staples” simultaneously.Therefore, the above description should not be construed as limiting,but merely as exemplifications of particular embodiments. Those skilledin the art will envision other modifications within the scope and spiritof the claims appended hereto.

What is claimed is:
 1. A method of assembling a buttress material with asurgical stapler instrument, comprising: providing a surgical staplerinstrument having a jaw assembly, the jaw assembly having an anvil and astaple cartridge, the staple cartridge having a pocket; positioning abuttress material over at least one of the anvil and staple cartridge,wherein said buttress material has preformed holes to receive legs of abuttress retaining a staple therethrough; inserting the buttressretaining staple through the buttress material such that the legs of thebuttress retaining staple extend into the pocket of the staple cartridgeand such that a backspan portion of the buttress retaining stapleextends across the buttress material, and the backspan portion of thebuttress retaining staple contacts a tissue contacting surface of thebuttress material; and crimping the legs of the buttress retainingstaple within the respective pocket of the staple cartridge so as toreleasably retain the buttress material against the staple cartridge. 2.The method according to claim 1, wherein a further staple has legs thatare inserted through the buttress material and through pairs of holes inthe anvil.
 3. The method according to claim 1, wherein the buttressretaining staple is frictionally retained in the pocket and isdetachable from the staple cartridge.
 4. The method according to claim1, wherein the buttress retaining staple is crimped to form bent legs.5. The method according to claim 1, wherein the buttress retainingstaples is formed from an absorbable or resorbable material.
 6. Themethod according to claim 1, wherein the staple cartridge includes rowsof staple containing pockets in addition to the pocket that receives thebuttress retaining staple.
 7. The method according to claim 1, whereinthe buttress retaining staple has inwardly bent legs that aresufficiently short so that the buttress material can pull away from thestaple.